A manhole is required when installing a rainwater leader on ____________ inch or larger pipe.

A manhole is required when installing a rainwater leader on 10-inch or larger pipe to facilitate maintenance and inspection of the drainage system. The code specifies this requirement to ensure that large pipes, which can accumulate debris or require periodic cleaning, can be accessed without excessive difficulty. A manhole allows for easy entry to examine the pipe condition, address blockages, or perform repairs, promoting the overall functionality and longevity of the drainage system.

The requirement for larger pipes ensures that maintenance personnel have adequate access to perform their duties safely and effectively, as larger pipes are typically more challenging to deal with once clogged or damaged. In contrast, smaller pipes may not require a manhole, as they can often be serviced using other access points or methods, making maintenance more manageable.